A beheaded Jesse Merlin proves an interesting guinea pig for Graham Skipper’s life serum in the best scene of “Re-Animator: The Musical.” Photo: Thomas Hargis

When in doubt, just throw stuff. It’s a tried-and-true approach, and “Re-Animator: The Musical” revels in it.

The first four rows of the theater are covered in plastic. Seats aren’t assigned, so you get a rain poncho if you pick the “splash zone.”

And splash it does. Based on the cult 1985 horror movie “H.P. Lovecraft’s Re-Animator,” in which a med student with a God complex resuscitates the dead, this New York Musical Theatre Festival production goes through a lot of fake blood, entrails and vomit.

The show follows the film faithfully, which shouldn’t be surprising considering that Stuart Gordon directed both.

Set at the med school of Miskatonic University — a location familiar to Lovecraft fans — the plot centers on the havoc wreaked by nerdy-creepy student Herbert West (Graham Skipper), who invents a life serum that works. With unpleasant side effects.

Best — or worst — of all is the evil Dr. Hill (Jesse Merlin, in fine voice), who tries to steal the formula.

Performed live by Brian P. Kennedy on keyboards, Mark Nutter’s score is serviceable. It’s not terrible, but nothing sticks out from the synthesized muck, except maybe lyrics like “My head was a swarm of buzzing bees/As I pondered the possibilities,” or Dan’s last song, which sounds suspiciously like “My Way.”

But while the film balanced black humor with genuine frights, the inexplicably sold-out “Re-Animator: The Musical” relies almost solely on schlock tactics and broad jokes. This is the approach favored by most B-movie adaptations, including the current “Terminator Too: Judgment Play,” which also supplies ponchos.

Here, what you do remember are the effects, which illustrate how much imagination can stretch a meager budget. The scene in which Herbert kills and then decapitates Dr. Hill is the highlight of the evening.

After a while, though, the geysers of gore feel like desperate ploys to grab attention, as if the show couldn’t decide if it should be in a theater or a Coney Island spook house.